The Flow Cytometry/Fluorescence Imaging Shared Resource provides NCCC investigators with advanced instrumentation for the study of cells. To this end, it aims to provide state-of-the-art flow cytometers and image analysis systems for acquisition of data; to provide computer hardware and software for the analysis of cellular data derived from these instruments; to train scientists in use of the instruments and software; to develop and implement new techniques for cell analysis; and to encourage communication among scientists on methods of common interest. For flow cytometry, the Shared Resource has four Becton Dickinson instruments. A FACStar Plus VIS/UV six-parameter cytometer with TurboSort upgrade is used for sorting and advanced applications. Two FACScan five-parameter cytometers and one FACSCalibur six-parameter cytometer are benchtop cytometers that are used for applications including immunophenotyping, cell cycle analysis, phagocytosis assays, and precursor frequency analysis of proliferating cells. The Resource also has three image analysis systems: a Bio-Rad MRC 1024 laser confocal system, a CompuCyte laser scanning cytometer, and a Zeiss Axiophot photomicroscope with a cooled CCD detector. Funding has just been received from the NIH Shared Instrumentation Grant for the purchase of a new confocal system. There is, within the Shared Resource, a wet lab for cell preparation and a computing area for analysis of flow and imaging data.